Abstract: The TPD-MS technique and the measurement of catalytic activity for toluene selective oxidation were used to study the thermal desorption properties of surface and lattice oxygen of V₂O₅ and V₂O₅ with additive Ag or Ag, Ni.The results showed that on the surfaces of the three samples the surface O^- and O^2- species were detected.With Ag or Ag, Ni added, the activation energy values(E_d)of the desorption of surface oxygen species(O^- and O_2-)decreased explicitly, and this shows that the Ed value of the sample containing Ag, Ni was the lowest, while the selectivity of benzaldehyde was the highest.In addition, for the samples of V₂O₅ and V₂O₅ with the additive Ag, Ni, a desorption peak which was mainly the lattice oxygen(O_2-)appeared at 968 and 734℃, respectively, and the Ed value for the sample containing Ag and Ni was also the lowest.

Key words: V₂O₅, Additive Ag(or Ag and Ni), Surface oxygen species, Selective oxidation of methylbenzene